27 cm. Beautiful but very cryptic forest kingfisher. Very few sightings or specimens. Largely rufous with blue wings, rump and tail with distinctive blue moustachial and eye-stripes and red bill. Similar spp.A. excelsus (formerly included with this species) has black rather than blue moustacial and postocular stripes and a much darker greenish black mantle. Sacred Kingfisher Todiramphus sancta has paler buff underparts and collar. Variable Kingfisher Ceyx lepidus is much smaller. Voice Calls before dawn and after dusk: a loud, ringing series of ko-ko-ko... notes.

Justification:
This spectacular species is judged to be Endangered on the basis of a very small estimated population which is suspected to be declining. However, further research may reveal it to be more common and not declining.

Actenoides bougainvillei is endemic to the island of Bougainville, Papua New Guinea (del Hoyo et al. 2001, Fry and Fry 1999, Dutson 2011). There are a few specimens, the last taken in 1938 (Mayr 1945, Cain and Galbraith 1956), and then no records until the 1980s. It is very unobtrusive and crepuscular and likely to be overlooked unless the call is known. Calls believed to be of this species were heard in 1986 on the edge of lowland swamp-forest near Arawa (Bishop 1987) and a pair was reportedly watched at a nest-hole in the 1980s (K. D. Bishop in litt. 1983). Local people around Panguna are familiar with the species and have shown one recently-killed bird to visiting birdwatchers but there are no other data on its distribution (P. Gregory pers. comm. 2016).

The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.

Trend Justification: There are no data on population trends; however, the species is suspected to be declining at a slow to moderate rate, owing to predation by introduced rats and cats, and possibly by habitat degradation.

Likely to be restricted to the interior of montane old-growth forest, with a recent record from 800 m (Dutson 2011), although calls thought to belong to the species have been reported from lowland swamp-forest (Bishop 1987). Very little is known about the species. There is a report of nesting in an arboreal termitarium (Mayr 1945, K. D. Bishop in litt. 1983, del Hoyo et al. 2001). Local people around Panguna report the species above 1100 m and have shown one recently-killed bird to visiting birdwatchers but there are no other data on its ecology (P. Gregory pers. comm. 2016).

It is potentially threatened by introduced rats and cats which are common even at high altitudes (Leary 1991). The species' montane forest habitat is above the altitude usually affected by logging or clearance for subsistence gardens.